This invention relates generally to the field of measuring, and in particular to the field of mass measurement. More specifically, the invention relates to techniques for measuring the mass of a substance that has been volumetrically metered.
In many fields, there is a need to precisely measure the mass of a substance. For example, substances such as drugs, chemicals, and the like may often need to have their mass measured. For instance, drugs are often prescribed in terms of unit dosages that are often determined based on the mass of the drug formulation. Therefore, the mass of the drug formulation contained in such unit dosages needs to be measured.
A traditional way to measure the mass of a substance is by use of a balance or a scale. Although effective in precisely measuring the mass of a substance, such techniques can be inefficient for commercial production of a product, such as when producing large volumes of unit drug dosages. For example, some unit dosages of drugs consist of a granular of powder drug formulation stored in receptacles, such as blister packs, capsules, caplets, or the like. To test whether the receptacle includes a unit mass of the drug formulation, the receptacle is opened and the powder is removed and weighed. Because of the destructive nature of the test, only periodic samplings are typically performed.
For some types of substances, a convenient way to meter is volumetrically. For example, substances such as powders, granular substances, and the like are easily measured by filling a known volume with the substance. However, merely filling a known volume with a substance does not guarantee that the metered substance has a known mass. For example, when volumetrically metering the substance, the density of the substance may change due to packing conditions, voids within the substance, and the like. Hence, in cases where the mass of the substance needs to be metered, volumetric metering may not guarantee an accurate result.
Hence, the invention is related to techniques for measuring the mass of a substance, and particularly the mass of a substance that has been volumetrically metered. In this way, the invention provides techniques for measuring the mass of a substance in a high throughput manner.